Overview
The NSF was established to standardize sanitation and food safety standards in the United States. For more information on NSF as it relates to walk-in coolers and freezers, check out our NSF Certifications Related to Walk-in Coolers and Freezers blog.
The NSF/ANSI 7 Standard establishes minimum food protection and sanitation requirements for the materials, design, manufacture, construction and performance of three styles of walk-in coolers and freezers:
- Storage Walk-in Coolers and Freezers
- Prefabricated Walk-in Coolers and Freezers
- Rapid Pull-down Walk-in Coolers and Freezers
NSF 7 Materials Requirements
NSF 7 Design & Construction Requirements
To ensure that food storage areas are constructed with materials that are appropriate for the use environment and are free from materials and construction methods that risk contaminating food with harmful microbiological organisms that would endanger the health of consumers, the design and construction of walk-ins are regulated by NSF.
Additionally, walk-in equipment must be designed and manufactured to prevent vermin and the accumulation of dirt, debris and moisture, and to allow for the inspection and maintenance of the walk-in and equipment it contains. Walk-ins require very specific and consistent cleaning, inspections and maintenance, and their construction must allow for this. Both food zones and nonfood zones of walk-ins must be readily accessible and cleanable.
Each refrigerated storage compartment shall have at least one temperature-indicating device that clearly displays the air temperature in the compartment.
Storage Walk-in Cooler and Freezer Requirements
Storage walk-in coolers shall be capable of maintaining an air temperature of 40°F (4°C) or lower in all refrigerated compartment interiors. Storage walk-in freezers shall be capable of maintaining an air temperature of 0°F (-18°C) or lower in all freezer compartment interiors.
Food storage compartments that are intended solely for the storage of packaged foods, and are appropriately labeled as such, shall conform to the splash zone material requirements of NSF 7, Sections 4 and 6 as well as NSF 7, Sections 5 and 6.
Equipment intended solely for the storage and display of packaged food products shall have a permanently attached label that states: “This equipment is intended for the storage and display of packaged products only.”
Storage coolers and freezers shall also meet the general “NSF 7 Materials Requirements” and “NSF 7 Design & Construction Requirements” noted above.
Prefabricated Walk-in Cooler and Freezer Requirements
NSF 7 Materials Requirements for Prefabricated Walk-in Coolers and Freezers
Galvanized and other zinc alloy-coated materials may only be used on the walls, ceilings, and attached hardware and components of walk-in coolers and freezers. Unless protected by an additional coating conforming to NSF/ANSI 51, galvanized and other zinc alloy-coated materials used in this application shall be at least as corrosion-resistant as G90 galvanized steel.
Coated materials, including galvanized materials, shall not be used on the floor of a walk-in cooler or freezer unless it is covered with a cement floor at the time of installation. PVC laminated steel or aluminum may be used as the finished floor of walk-in coolers and freezers provided that the substrate is at least as corrosion resistant as G90 galvanized steel.
NSF 7 Design & Construction Requirements for Prefabricated Walk-in Coolers and Freezers
To seal joints between panels, gaskets shall be applied to panel perimeters at the time of manufacture. The gaskets shall conform to requirements in NSF/ANSI 7 Section 4 and must be permanently attached.
Internal angles or corners of less than 135° in a food zone shall be smooth and have a minimum continuous radii of 1/4 inch.
Door sills shall be designed to facilitate cleaning of the interior floor, and doors shall be non-sweeping. Doors must be capable of opening from the inside, even when locked. Sliding doors on walk-in coolers and freezers shall be readily removable, or easily cleanable as installed.
Walk-in units with prefabricated floors shall not have floor drains.
Refrigeration components of food storage equipment shall be accessible for necessary cleaning and maintenance.
Manufacturers of walk-in units not supplied with refrigeration components shall recommend minimum BTU ratings for ambient temperatures of 75°F, 80°F, or 100°F. If a manufacturer supplies only components for the construction of a walk-in cooler or freezer, the manufacturer shall specify the U-Value of the panels in its literature.
Prefabricated walk-in coolers and freezers shall also meet the general “NSF 7 Materials Requirements” and “NSF 7 Design & Construction Requirements” noted above.
Prefabricated Walk-in Coolers and Freezers Used for the Storage of Food in the Original Sealed Package
NSF 7 Materials Requirements for Prefabricated Walk-in Coolers and Freezers Used for Packaged Foods Only
Prefabricated floors may be constructed of galvanized and other zinc-alloy-coated materials at least as corrosion resistant as G90 galvanized steel. If tread plate flooring is to be applied over galvanized floors, it shall be fastened and sealed per the manufacturer’s instructions.
PVC laminated steel or aluminum flooring material is acceptable but shall be capable of withstanding abrasion, impact and adhesion resistance as outlined in NSF 7, Sections 8.4.2, 8.4.3 and 8.4.4.
NSF 7 Design & Construction Requirements for Prefabricated Walk-in Coolers and Freezers Used for Packaged Foods Only
Walk-ins without prefabricated floors shall be manufactured so that seams formed between the walls and floor, or base, may be closed and sealed upon assembly.
Door sills shall be designed to facilitate the cleaning of the walk-in floor, and doors shall be non-sweeping. Doors must be capable of opening from the inside, even when locked.
Anti-skid adhesive strips shall be exempt from the requirement that materials be smooth and cleanable.
Manufacturers of walk-in units not supplied with refrigeration components shall recommend minimum BTU ratings for ambient temperatures of 75°F, 80°F or 100°F. If a manufacturer supplies only components for the construction of a walk-in cooler or freezer, the manufacturer shall specify the U-Value of the panels in its literature.
Prefabricated walk-in coolers and freezers used for the storage of food in the original sealed package shall have a permanently attached label that states: “This equipment is intended for the storage of food in the original sealed package only.”
Prefabricated walk-in coolers and freezers used for the storage of food in its original sealed package shall also meet the general “NSF 7 Materials Requirements” and “NSF 7 Design & Construction Requirements” noted above.
Rapid Pull-down Cooler and Freezer Requirements
This Section contains NSF requirements for rapid pull-down coolers and freezers, which shall meet the requirements of NSF 7, Sections 4 and 5. Food storage walk-ins shall meet food zone material requirements of Section 4 and splash zone design and construction requirements of Sections 5 and 10.
Internal angles or corners of less than 135° in a food zone shall be smooth and shall have minimum continuous radii of 1/4 inch except for the angles formed by the ceiling and wall connections and angles formed where an evaporator is mounted to the interior surfaces.
The manufacturer of a remote walk-in cooler system shall specify the load requirements BTU/hr (kW/hr) and the applicable evaporator temperature for each unit at its test condition.
Refrigeration components of food storage equipment shall be accessible for necessary cleaning and maintenance.
Rapid pull-down coolers and freezers shall have a permanently attached label that states:
“This unit is capable of reducing the internal temperature of the contents from 135°F (57°C) to 40°F (4°C) within 4 hours.”
Rapid pull-down coolers and freezers shall also meet the general “NSF 7 Materials Requirements” and “NSF 7 Design & Construction Requirements” noted above.
Conclusion
The NSF/ANSI 7 Standard was created to prevent the contamination of foods in refrigerated spaces where they are stored. The goals of the NSF/ANSI 7 Standard are:
- To ensure walk-in coolers and freezers are constructed with materials that are appropriate for the environment where they are used.
- To ensure walk-ins are free from construction methods that risk contaminating food from harmful microbiological organisms.
- To ensure the cleanability of walk-in surfaces.
Our sales teams are informed and knowledgeable about NSF as it relates to walk-in coolers and freezers, to learn more about how NSF/ANSI 7 relates to your project needs contact us today.
Citation: NSF/ANSI 7 (2019) “Commercial Refrigerators and Freezers”, NSF International Standard/American National Standard, Ann Harbor, MI, www.nsf.org.
